1. Field of the Invention
This invention relates to an ink cartridge which is removably mounted in ink jet printers.
2. Related Art
FIG. 1 shows an ink cartridge. The ink cartridge 100 has a cartridge casing 101 comprised of an upper casing 102 and a lower casing 103. The cartridge casing 101 contains ink absorbent 104. The lower casing 103 has a bottom formed with an ink supply block 105 projecting downward. The ink supply block 105 is constructed such that it can be fitted on an inserting portion of a print head of a printer, through which ink is introduced into the print head, so as to facilitate coupling of the ink cartridge 100 to the print head and make it possible to mount the cartridge 100 even in a printer which is subject to vibration. More specifically, the ink supply block 105 is formed with a delivery port 106 opening in a bottom surface thereof, and a supply passage 107 which extends from the delivery port 106 to the inside of the cartridge casing 101 and serves both as an ink passage and as a portion for receiving the inserting portion of the print head. Further, at an upstream end of the supply passage 107, there is provided a filter 108 in a manner separating the supply passage 107 and the ink absorbent 104 from each other. On the other hand, the upper casing 102 is formed therethrough with an ink-charging port 109, and on a top surface of the upper casing 102, there is formed a meandering air groove 110 leading to the ink-charging port 109.
The delivery port 106 of the ink cartridge 100 constructed as above is covered with a delivery port-covering film 111 by attaching the same to the bottom surface thereof by thermo compression bonding. Then, the ink cartridge 100 is put in a vacuum chamber, where ink is charged into the ink cartridge 100 via the ink-charging port 109. Further, an ink-charging port-covering film 112 is attached to the top surface of the upper casing 102 by thermo compression bonding, to thereby block the ink-charging port 109 and cover the air groove 110. In this state, the cartridge 100 is enclosed in a sealed package, and supplied to users. Before mounting the ink cartridge 100 in a printer, the user peels off part of the ink-charging port-covering film 112 to thereby expose an open end of the air groove 110 to the atmosphere, and then opens the delivery port 106 by peeling off the delivery port-covering film 111. In this state, the ink cartridge 100 is fitted on the inserting portion of the print head of the printer.
In the case of the ink cartridge 100 described above, when ink is charged into the cartridge 100, the ink flows through the filter 108 to fill the supply passage 107. Therefore, before mounting the cartridge 100 in the printer, when the user, after peeling off the ink-charging port-covering film 112, turns the ink cartridge 100 upside down and peels off the delivery port-covering film 111, the ink collected in the supply passage 107 is liable to spill out and stain the user's hands. Further, the ink also tends to spill out when the user turns the ink cartridge 100 over again to fit the same on the inserting portion of the print head, so that the user has to remove the collected ink from the supply passage 107 before using the cartridge 100. This makes the mounting of the cartridge 100 very troublesome.